Technical Field
This disclosure relates generally to the field of gas valves and more specifically to gas valve that automatically shuts off when an earthquake occurs.
Background Information
Earthquakes can occur in any land mass that is close to a tectonic plate located under the surface of the earth. Earthquakes can do extensive damage due to the sometimes-violent shaking motion that is precipitated by the slippage of one tectonic plate over another tectonic plate. Many homes and offices are heated by natural gas. Some homes and offices also have stove tops that also use natural gas to cook food. If a gas line is ruptured during an earthquake, there is a possibility that an explosion can occur which could do serious damage to a structure such as a home or office.
In an effort to automatically shut off gas when an earthquake occurs, a mechanical earthquake valve has been developed and marketed. The basic operating premise of the valve is that a sphere, or other physical object is caused to fall off a pedestal within a valve body. The sphere rolls down via gravity to then obstruct the gas inlet port of the valve, thereby preventing gas from entering a house or office and preventing the possible explosion that might occur when a gas line ruptures due to the violent shaking of an earthquake. This type of valve can save lives and has even been mandated by some state legislatures.
However, there are deficiencies in the prior technology. Mechanical type earthquake valves can be accidentally activated if the valve body is bumped into, or if a large truck rumbles down the street and causes enough shaking to dislodge the ball sitting on its pedestal, causing it to roll down and shut off the gas. Generally, it requires calling the local utility company to have someone come to the residence or office location to re-set the valve to the open position. Additionally, mechanical earthquake valves cannot be shut off or on remotely. Also, a mechanical valve cannot be activated by other adverse conditions such as extreme heat from a fire.